It was the first night of Kwanzaa, and the basement of Union Temple Baptist Church in Anacostia was filled with hundreds of men and women enjoying the 45-year-old African American celebration.

The Rev. Willie Wilson, pastor of Union Temple, shouted “Habari Gani?” a Swahili greeting that means “What’s happening?” Members of the crowd, many in African attire, responded with a spirited “umoja,” or unity.

“At Union Temple, Kwanzaa is not just a seven-day observance, it is a way of life,” Wilson said in an interview at the event Monday. “The principles of Kwanzaa need to be revived and kept alive: unity, self-determination, collective work. . . . It is good to know principles, but the value is in practicing them.”

Kwanzaa observances may be dwindling elsewhere, but its values are part of the Southeast congregation’s cultural fabric.

“Kwanzaa is a time for us to reconnect with our heritage and our traditions,” said C.R. Gibbs, a Union Temple member and historian who specializes in the African diaspora. “Many African Americans are not taught who they are or where they came from.”

Aini-Alem Dennis, 10, from left, Mikalah Davis, 14, and Leilani Gill, 11, perform with the Farafina Kan Youth Ensemble during A Kwanzaa Celebration at Our Lady of Perpetual Help Church on Dec. 29 in Washington. (Hamil R. Harris/The Washington Post)

Maulana Karenga, a professor of African studies at California State University at Long Beach, founded the holiday, which traces its roots to the black nationalist movement.

On Wednesday night, more than 300 people packed Union Temple as Karenga urged them to shed thinking that makes them “American by habit” and to instead think of themselves as “Africans by choice.” The aim, he said, is to strive for excellence in social, academic and personal terms.

“If we are ever to rebuild the movement, we must think of ourselves as what we are: African people,” said Karenga, sporting a shaved head, goatee and a voice both booming and raspy. The crowd responded with a standing ovation, and many flocked to take his photo.

Umoja is the first of Kwanzaa’s seven principles. The others are self-determination, collective work and responsibility, cooperative economics, purpose, creativity and faith.

At a time when many churches have focused on a “prosperity gospel,” Wilson said, the principles of Kwanzaa are as important as ever.

“This me-myself-and-I mentality has robbed us of our collective work and responsibility that results in our upward mobility,” Wilson said. “At one time, we as a people were forced to support each other. Since that time, we have lost a lot of that commitment to each other.”

Zarinah Shakir, a veteran radio and television broadcaster and producer, has celebrated Kwanzaa for more than 30 years. Shakir, who is a Muslim and lives in Southeast, said the holiday transcends faith and seems to be making a comeback.

“I think Kwanzaa . . . is on the rise again because of all that is going on in the world,” Shakir said. “People are looking for answers. They are looking for something to assist them in a positive way, and there is nothing more positive than Kwanzaa.”

Ayo Handy-Kendi, founder and director of the African American Holiday Association, has also noticed a surge in interest in Kwanzaa.

“I have watched Kwanzaa grow tremendously,” she said. I have seen young people grow up and are now watching them bring their children to the Kwanzaa gatherings. This is how a holiday becomes an institution.”

Handy-Kendi plans to serve as emcee at the 42nd annual Kwanzaa children’s party Saturday at NationHouse on Park Road NW. On Sunday, Plymouth Congregational United Church of Christ on North Capitol Street NE will host an event featuring dancers, drummers and spiritual leaders.

Gloria Johnson, a lawyer, said she and her husband, Hiram Tanner, an engineer, have celebrated Kwanzaa since they began dating in the 1970s.

“My husband and I got married on the principles of Kwanzaa,” Johnson said at Union Temple. “We had seven bridesmaids and male attendants, and each bridesmaid spoke about a principle of Kwanzaa as they lit a candle.”

Their only daughter — one of three children — is named Nia, which means purpose, one of the celebration’s core concepts.